Reliable Card Detection in a Cpci System

1. A computer system including a circuit board, said system comprising: a slot coupled to a front side of said circuit board; a plurality of connectors affixed to said circuit board in alignment with said slot, said plurality of connectors including a first connector; a plurality of connector-pins extended in a direction substantially perpendicular to and away from said circuit board, and having a column and row arrangement within said connectors, said first connector including first and second connector-pins among said plurality of connector-pins; a register having an input line and an output line, said input line connected to a voltage source through a pull-up resistor, said first connector-pin connected to said input line of said register; and a circuit having an input terminal and connected to said first connector-pin through said register, said register connected to said input terminal of said circuit via said output line of said register, wherein depending on a voltage level of said first connector-pin, said register transmits one of a high and low signal to said input terminal of said circuit, said circuit detects a presence of a front card in said slot based on said one of high and low signal; wherein said circuit is at least one of a hot swap controller, a CPU, and a status indicator and wherein said hot swap controller is connected to said second connector-pin via a signal line, said hot swap controller adapted to distinguish between the insertion of a hot swappable front card and a non-hot swappable front card depending on said one of high and low signal and a voltage level of said second connector-pin.

2. The computer system of claim 1 , wherein said register is inserted into a slot of said circuit board and is connected with said circuit board via said input line of said register through said first connector-pin.

3. The computer system of claim 1 , wherein said front card comprises third and fourth connector-pins for mating with said first and second connector-pins.

4. The computer system of claim 3 , wherein said front card comprises a non-hot swappable front card, and said third and fourth connector-pins are connected to a ground layer of said front card.

5. The computer system of claim 3 , wherein said front card comprises a hot swappable front card, and said third connector-pin is connected to a ground layer of said front card and said fourth connector-pin is connected to a voltage source through a pull-up resistor.

6. The computer system of claim 1 , wherein said column and row arrangement of said connector-pins include first and second columns of connector-pins, said connector-pins of said first and second columns connected to a ground layer of said circuit board, except for said first connector-pin.

7. The computer system of claim 6 , wherein said connector-pins in said first and second columns are connected to said ground layer, except for those connector-pins located in a key area, said key area comprising a connector key that can only mate with an appropriate front card.

8. The computer system of claim 1 , wherein said first connector further comprises fifth and sixth connector-pins, and said fifth and sixth connector-pins are connected via signal lines to said circuit.

9. A circuit board having a front side, said circuit board comprising: a plurality of slots coupled to said front side of said circuit board; a plurality of connectors disposed within each of said plurality of slots and including a first connector in each of said slots, said respective first connectors of said slots including a first connector-pin and a second connector-pin; a plurality of connector-pins disposed in an arrangement of a plurality of columns and rows in each of said connectors, said plurality of columns including first and second columns, said connector-pins in said first and second columns connected to a ground layer of said circuit board, except for said first connector-pins in said first connectors; a input/output device having a plurality of input lines and output lines, each of said input lines connected to a voltage source through a pull-up resistor, and said first connector-pins in each of said slots connected to said input/output device via said respective input lines; and a circuit having a plurality of input terminals and connected to said first connector-pins through said input/output device, and said input terminals of said circuit being connected to said output lines of said input/output device, wherein depending on voltage levels of said respective first connector-pins, said input/output device transmits respective signals to said corresponding input terminals of said circuit, said circuit detects a presence of a front card in corresponding ones of said slots depending on said respective signals; wherein said circuit is a hot swap controller, said hot swap controller being connected to said second connector-pins via respective signal lines, said hot swap controller adapted to distinguish between the insertion of a hot swappable front card and a non-hot swappable front card in said slots depending on respective voltage levels on said first and second connector-pins of said respective slots.

10. The circuit board of claim 9 , wherein said first and second columns are located at an outermost column of said plurality of columns of said plurality of connectors.

11. The circuit board of claim 9 , wherein corresponding ones of said first connector-pins are at one of a positive voltage and negative voltage with respect to a potential of said ground layer when a front card is not present in corresponding ones of said slots.

12. The circuit board of claim 9 , wherein corresponding ones of said first connector-pins are connected to a ground layer when said front card is inserted in corresponding ones of said slots.

13. The circuit board of claim 9 , wherein said input/output device is configured as a front card, said front card mated with one of said slots of said circuit board.

14. The circuit board of Claim 9 , wherein said input/output device comprises a register.

15. A computer system including a circuit board, said system comprising: a slot coupled to a front side of said circuit board; a plurality of connectors affixed to said circuit board in alignment with said slot, said plurality of connectors including a first connector; a plurality of connector-pins extended in a direction substantially perpendicular to and away from said circuit board, and having a column and row arrangement within said connectors, said first connector including first and second connector-pins among said plurality of connector-pins; a register having an input line and an output line, said input line connected to a voltage source through a pull-up resistor, said first connector-pin connected to said input line of said register; and a circuit having an input terminal and connected to said first connector-pin through said register, said register connected to said input terminal of said circuit via said output line of said register, wherein depending on a voltage level of said first connector-pin, said register transmits one of a high and low signal to said input terminal of said circuit, said circuit detects a presence of a front card in said slot based on said one of high and low signal, wherein said circuit can distinguish between the presence of a hot swappable front card and a non-hot swappable front card.

16. The computer system of claim 15 , wherein said circuit further comprises a hot swap controller for distinguishing between the presence of a hot swappable front card and a non-hot swappable front card.

17. The computer system of claim 15 , wherein said circuit further comprises a hot swap controller connected to said second connector-pin via a signal line, said hot swap controller distinguishing between the presence of a hot swappable front card and a non-hot swappable front card based on said one of high and low signal and a voltage level of said second connector-pin.

18. A circuit board having a front side, said circuit board comprising: a plurality of slots coupled to said front side of said circuit board; a plurality of connectors disposed within each of said plurality of slots and including a first connector in each of said slots, said respective first connectors of said slots including a first connector-pin and a second connector-pin; a plurality of connector-pins disposed in an arrangement of a plurality of columns and rows in each of said connectors, said plurality of columns including first and second columns, said connector-pins in said first and second columns connected to a ground layer of said circuit board, except for said first connector-pins in said first connectors; a input/output device having a plurality of input lines and output lines, each of said input lines connected to a voltage source through a first pull-up resistor, and said first connector-pins in each of said slots connected to said input/output device via said respective input lines; and a circuit having a plurality of input terminals and connected to said first connector-pins through said input/output device, and said input terminals of said circuit being connected to said output lines of said input/output device, wherein depending on voltage levels of said respective first connector-pins, said input/output device transmits respective signals to said corresponding input terminals of said circuit, said circuit detects a presence of a front card in corresponding ones of said slots depending on said respective signals; wherein said front card comprises at least one of a hot swappable front card and a non-hot swappable front card, wherein said hot swappable front card has a second pull-up resistor located within said hot swappable front card, and wherein said first pull-up resistor is not located within said hot swappable front card.

19. The circuit board of claim 18 , wherein said circuit distinguishes between the presence of said hot swappable front card and said non-hot swappable front card.

20. The circuit board of claim 18 , wherein said circuit comprises at least one of a hot swap controller, a CPU, and a status indicator.